ZE
ZESTEXAM

AFCAT Nutrition in Plants & Animals

Study Material · Concept Notes · Shortcuts

This page covers AFCAT Nutrition in Plants & Animals with complete concept notes, 4 graded practice MCQs, key points and exam-specific tips. Free to study.

0 PYQs
none yet
4 Practice
MCQs
8 Key Points
to remember
Free
no login needed
Take Free Mock →Full Practice Set
Also for:NDACDSAgniveerCAPF
PYQs
0
Practice
4
Key Points
8
Access
Free
Concept Notes

Nutrition in Plants & Animals— Rules & Concept

1.Core Concept

Read this first — the foundation of the topic

NUTRITION IN PLANTS & ANIMALS --- CORE CONCEPT ---

Nutrition is the process by which living organisms obtain food and use it for energy, growth, and repair. Plants and animals get their nutrition in completely different ways. This is one of the most important distinctions in Biology for competitive exams. --- KEY RULES / PROPERTIES ---

NUTRITION IN PLANTS: Plants are called AUTOTROPHS — they make their own food. They do this through PHOTOSYNTHESIS.

Photosynthesis happens in the CHLOROPLAST, inside the CHLOROPHYLL pigment (which gives leaves their green colour). The process uses:

• Sunlight (energy source) • Carbon dioxide (CO2) — taken in through tiny pores called STOMATA

• Water (H2O) — absorbed through roots The plant produces GLUCOSE (food) and releases OXYGEN as a byproduct.

---

2.Formula Block

Memorise — at least one formula appears in every paper
6CO2 + 6H2O + Sunlight → C6H12O6 (Glucose) + 6O2
In words: Carbon dioxide + Water + Light energy → Glucose + Oxygen
In humans, digestion breaks food into simpler molecules so the body can absorb them. Key organs: Mouth → Oesophagus → Stomach → Small Intestine → Large Intestine.

--

Photosynthesis Equation (must memorise):

Plants can also get nutrition without sunlight through CHEMOSYNTHESIS (e.g., some bacteria), but this is rarely tested at RRB level.

Some plants are HETEROTROPHS too:

• Parasitic plants: Cuscuta (Amarbel) — takes food from host

• Insectivorous plants: Venus Flytrap, Pitcher Plant — trap and digest insects

• Saprophytic plants: feed on dead matter (e.g., some fungi)

NUTRITION IN ANIMALS:

Animals are called HETEROTROPHS — they cannot make their own food. They depend on plants or other animals.

Types of animal nutrition:

• Herbivores: eat only plants (Cow, Rabbit)

• Carnivores: eat only animals (Lion, Tiger)

• Omnivores: eat both (Human, Bear)

• Parasites: live on/in a host (Tapeworm, Lice)

Key enzyme fact: AMYLASE (in saliva) breaks starch into sugar. PEPSIN (in stomach) breaks protein. LIPASE breaks fats.

---

3.Exam Patterns

What examiners ask — read before attempting PYQs
Trick 2 — Enzyme Memory

'A-P-L' → Amylase=starch, Pepsin=protein, Lipase=fat

Remember

APL = 'A Plant's Life' (just a

4.Memory Hook

Remember this — never confuse the two again

). ---

5.Worked Example

Solve this step-by-step before moving on
1
Step 1

Write the equation — 6CO2 + 6H2O + Sunlight → C6H12O6 + 6O2

2
Step 2

The equation shows 6CO2 is used on the left side — this matches our question.

3
Step 3

Read the right side — 6O2 molecules are released.

4
Step 4

The food molecule produced is C6H12O6, which is GLUCOSE. Answer: 6 molecules of Oxygen are released, and Glucose is produced. ---

6.Exam Traps

Common mistakes students make — avoid these

--- Students confuse RESPIRATION with PHOTOSYNTHESIS. Remember: Photosynthesis TAKES IN CO2 and RELEASES O2. Respiration does the OPPOSITE — takes in O2, releases CO2.

Also, many students forget that Cuscuta is a PARASITIC plant, not insectivorous.

Key Points to Remember

  • Plants are AUTOTROPHS — they make their own food through photosynthesis using sunlight, CO2, and water.
  • Photosynthesis equation: 6CO2 + 6H2O + Sunlight → C6H12O6 (Glucose) + 6O2
  • Photosynthesis occurs in CHLOROPLASTS, in the green pigment called CHLOROPHYLL.
  • CO2 enters the leaf through tiny pores called STOMATA; water is absorbed by ROOTS.
  • Animals are HETEROTROPHS — they depend on other organisms for food (plants or animals).
  • Cuscuta (Amarbel) is a PARASITIC plant; Venus Flytrap and Pitcher Plant are INSECTIVOROUS plants.
  • Key digestive enzymes: Amylase → breaks starch; Pepsin → breaks protein; Lipase → breaks fats.
  • Herbivores eat only plants, Carnivores eat only animals, Omnivores eat both (humans are omnivores).

Exam-Specific Tips

  • The green pigment responsible for photosynthesis is CHLOROPHYLL, located in CHLOROPLASTS.
  • Oxygen is a BYPRODUCT of photosynthesis — it is released through stomata.
  • Cuscuta (Amarbel) is a classic example of a PARASITIC plant that gets nutrition from its host.
  • PEPSIN is the enzyme found in the stomach that digests PROTEINS; it works in an acidic medium.
  • SALIVARY AMYLASE (Ptyalin) is the enzyme in saliva that begins the digestion of STARCH in the mouth.
  • Venus Flytrap and Pitcher Plant are INSECTIVOROUS (carnivorous) plants that trap insects for nitrogen.
  • The site of absorption of digested food in humans is the SMALL INTESTINE (specifically the villi).
  • Chemosynthesis is the process used by some bacteria to make food WITHOUT sunlight, using chemical energy.
Practice MCQs

Nutrition in Plants & Animals — Practice Questions

4graded MCQs · easy to hard · full solution & trap analysis

All MCQs →
Practice 1easy

During photosynthesis in green plants, which of the following is the primary function of chlorophyll?

Practice 2medium

Which part of the human digestive system is responsible for the absorption of most digested nutrients into the bloodstream?

Practice 3medium

During photosynthesis in green plants, the light-dependent reactions occur in the thylakoid membranes of chloroplasts and produce two essential products. Which of the following correctly identifies both products of the light-dependent reactions?

Practice 4hard

During photosynthesis in a green plant, if the light intensity is increased from 100 lux to 500 lux while keeping temperature and CO₂ concentration constant, the rate of photosynthesis initially increases but then plateaus. Which of the following best explains why the rate does NOT continue to increase proportionally at higher light intensities?

60-Second Revision — Nutrition in Plants & Animals

  • Remember: Photosynthesis formula — 6CO2 + 6H2O + Sunlight → C6H12O6 + 6O2. Learn this by heart.
  • Remember: Photosynthesis ABSORBS CO2 and RELEASES O2. Respiration is the exact opposite.
  • Trick: APL — Amylase digests starch, Pepsin digests protein, Lipase digests fat.
  • Trap: Cuscuta = PARASITIC plant (NOT insectivorous). Venus Flytrap = INSECTIVOROUS plant.
  • Remember: Plants = Autotrophs (make own food). Animals = Heterotrophs (depend on others).
  • Formula location: Photosynthesis happens in CHLOROPLAST. CO2 enters through STOMATA. Water through ROOTS.
  • Trap: Oxygen in photosynthesis comes from the splitting of WATER molecules, not from CO2.
←Ecosystems & Environment
Studied the notes? Now test yourself
See how Nutrition in Plants & Animals appears in the real AFCAT paper
Full timed mock · Instant All-India percentile · Free
Start Free Mock →Practice Panel
✓ Free forever for basic prep✓ No app download✓ Real exam-pattern questions
Test Nutrition in Plants & Animals under exam conditions
Free AFCAT mock · instant rank · no login
Free Mock →